4 Common Signs of King Pin Wear on a Semi-Truck

Semi-truck safety is essential for hauling cargo across the country. However, you can be at risk if you can’t securely attach a semi-truck to the trailer. Here are some common signs of king pin wear on a semi-truck.

Worn-Down Throat

Tightening your tractor and trailer together should work easily with a proper king pin. However, if you notice the fifth wheel trailer adjustment struggles to tighten, it’s most likely a bad king pin.

The throat of the king pin becomes incredibly worn down, not allowing the fifth wheel trailer adjustment to grip onto anything. This creates an unsafe securing issue, so replacing your king pin as soon as possible is crucial before hauling.

Worn-Down Shoulder

Similar to a worn-down throat, a worn-down shoulder can impact the attachment of a fifth wheel trailer adjustment. When the shoulder of a king pin becomes worn down, it makes it impossible for it to tighten properly.

You can't safely haul your trailer because there’s nothing for the fifth wheel trailer to tighten on. So installing a replacement is necessary.

Coupling Difficulty

The coupling of a semi-truck connects the tractor and the trailer, supporting the payload. If you notice signs of struggle for truck-to-trailer coupling, it could result from a worn king pin. A well-preserved, functioning king pin makes for easy coupling.

Furthermore, if your trailer and tractor can couple properly but have difficulty uncoupling, this could also occur due to a bad king pin. A bent king pin can develop issues with coupling and uncoupling, so the solution is to have it fixed as soon as possible. Without doing so, it can create unsafe hauling conditions.

No Lubrication

Another common sign of a worn semi-truck and trailer king pin connection is the lack of lubrication. Poorly lubricated king pins become worn excessively and quickly. Maintaining a lubricated king pin is a must for reducing tractor fifth wheel trailer grinding. Without proper lubrication, uneven and premature wearing can create unsafe hauling environments.

Poor lubrication signs include premature wear and king pin galling. These result in unwanted surface contact. Insufficient lubrication is usually the issue if you notice significant wear before your king pin’s lifespan ends. Unfortunately, you must have your king pin replaced to ensure operator and rig safety in this case.

Van Horn Truck Parts offers high-quality semi-truck and trailer parts for competitive prices. Our semi-truck and trailer part allow your semi-truck to operate smoothly, including our king pin kits and sets, tie rod ends, power steering pumps, draglinks, and more. If you have any questions, contact us today.